Improvement in packings for steam-condenser tubes



LIGHTHALL.

iPackings for Steam-Condenser Tubes.'-

Patented Nov.10,1874..

UNITED STATES PATr-NHLEFIE- WILLIAM A. LIGHTHALL, OF BROOKLYN NEW YORK.

IMPROVEMEN'IV IN PACKINGS FOR STEAM-CONDENSER TUBES.

Specification forming part of Letters Patent No. 156,670, dated November 10, 1874; application filed July 31, 1874.

To all whom it may concern Be it'known that I, WILLIAM A. LIGHT- HALL, of the city of Brooklyn, in the county of Kings, State of New York, have invented a new and Improved Packing for Steam-Condenser Tubes, of which the following is a speciiication: Y

My invention relates to the formation of water and steam tight joints in tubular steam-condensers, between the tubes and the head-sheets thereof, without the use of a follower; and consists in a paper tube 0r hollow cylinder, formed of a continuous coil of sheet-paper, with a thin pellicle of glueinterposed between the'folds of the coil, the walls of the cylinder being consolidated and the contained glue incorporated With the paper by severe pressure, and such cylinder being made, when completed as a manufacture, to' fit tightly the tube to be packed, and made completely to lill the annular space around the cylinder in the headsheet, whereby may be formed, without the use of a follower, a permanently steam and water tight joint, which will permit of the movement of the tube in the packing-cylinder without displacing the packing.

There are peculiar conditions to be met in forming without a follower a permanent, satisfactory, steam-tight, yet movable, joinder of the tubes with the head-sheets in a steam-condenser, among which the following may be named: The tubes must be susceptible of longitudinal motion in the heads, to admit of their expansion and contraction with varyingdegrees of heat to which in use they are subjected, as a rigid joint would result iu bending the tubes or tearing them away from the headsheets. The packingor material used to form the joint between the tube and the head-sheet must be something that will not be worn away by the above-named motion; otherwise the joint, no matter how tight it might be at first, would soon become loosened, so as to leak steam and water; or there must be a compensation for such wear in the elasticity of the material. The material must be capable of bearing without injury the heat of the steam introduced into the condenser for condensation. It mustbe something that will not itself oxidize, and will not permit the oxidation of the tube or sheet-head at the points of contact. It must be susceptible in some degree of absorbing moisture, and thereby expanding and causing a perpetual elastic pressure against the walls of the aperture in the headsheet on one side, andthe exterior surface of the tube on the other; and it must be of such a nature and construction that the friction or adhesion between the external surface of the packing and the walls of the aperture iu the head-sheet is sufficient to hold, without the use of what is knownas a follower, the packing securely at rest in its seat, notwithstanding the longitudinal movement of the tube from expansion and contraction.

It is difficult to make a packing for condenser-tubes embodying all the characteristics above named; and l am not aware of any packing in use that does so. If what is denominated a follower (a device well known under that name) is used, there are many materials, such as soft metal, hemp, oakum, rubber, paper-pulp, and similar substances, by which a tight, yet movable, joint may be formed; but the first cost of the follower is very great, and while this device is one by which a joint when loose may be tightened, constant care, inspection, and frequent tightening up 7 of the follower are necessary to maintain tight joints. The object of my invention is to dispense with this expensive and troublesome device (the follower) by furnishing a packing formed of paper complete in itself, by the use of which, withouta follower, a permanently steam-tight, but movable, joint may be formed between the tubes and head-sheets of steam-condensers.

In carrying out my invention, I take a sheet of common thin paper, and spread over one side of it a very thin covering of glue. The glue must have very little consistency, and a small quantityonly be used, to the end that in the subsequent treatment of the paper the glue will be very completely incorporated into its substance. Thus' glued, I wind the sheet upon a mandrel the diameter of which is just equal to that of the tube for which the packing is designed. Sufficient paper should be thus wound upon the mandrel to form a tube the external diameter of which shall be considerably greater than the diameter of the aperture in the sheet-head of the condenser,

. packing for the end of a condenser-tube.

into which the said tube is designed to be packed. Unless the sheet or strip of paper used is itself of suitable width to make only a single tube of the length desired, the tube, made as above, is cut into sections of the desired length, each section constituting the In this condition, although the paper may have been rolled up as tightly vas it is practicable to roll it by hand or by machinery, the body of the cylinder formed is too soft and pervious by water to answer the purpose designed. It is essential that it be subjected to severe pressure in order to change this condition, incorporate the glue into the substance of the paper, and compact the whole and give it greater solidity. To this end I place the sections upon an iron or steel mandrel of the same diameter as the interior of the sections, and force it, while upon the mandrel, through a die of suitable construction, whereby the,

walls of the cylinders or sections are considerably reduced in thickness, and the eX- ternal diameter reduced to that of the aperture in the sheet-head of the condenser in which they are intended to be placed, thus compressing and compaetin g the several folds of paper together. After this compressing 'operation an examination will show that the glue has disappeared into the body of the paper, and a substance has been formed of combined paper and glue having the peculiar characteristics hereinbefore named, which specially adapt to the office of packing condensertubes-that is to say, while neither water nor steam can pass through it, it will, by contact with moisture, absorb it sufficiently to be eX- panded thereby to form a tight joint in use in a steam-condenser. Parting with its absorbed water very slowly, it does not readily contract by heat in the absence of water in-the condenser; it contains nothing that can contribute to the oxidation of the tubes or tube-sheets with which it is in contact; it will bear, without fracture, the percussion and swaging necessary to compact it in its seat in the sheethead around the pipes, and when so swaged will retain permanently` the shape and position thus given to it. and while permitting the tube,

While it expands or contracts, to slide in the packing, will remain securely iixed in the headsheet by adhesion to it and, finally, it forms a packing that is cheaply and easily produced and applied.

Of the drawings, Figure l is a central longitudinal section of the coil of paper and glue designed for my packing. Fig. 2 is a crosssection of the same. Fig. 3 is a side elevation ofthe same. Fig. 4 is a cross-section, and Fig. 5 a central longitudinal section, of the same coil after its walls have been compacted and consolidated by severe pressure. Fig. 6 is a vertical central section ofthe die and mandrel which may be used for compressii'lg and consolidating the said coil, showing a coil forced in to the die upon the mandrel. Fig. 7 is a similar section, showing the mandrel withdrawn from the coil in the die, and having received upon it another coil, in the act of descending with such coil into the die, whereby the coil already in the die will be forced through and completed. Fig. 8 is a vertical section of a sheet-head of a steam-condenser, showing two apertures for tubes, one containing the prepared paper cylinder-packin g ready to receive the tube, and the other showing the tube in the paper cylinder and the cylinder swaged down to complete the joint.

A represents a vertical section, and A a cross-section, of the coil of paper as it has been rolled upon a mandrel, with a thin pellicle of glue interposed between the folds. B is a die, and C a mandrel suitable for compressing the coil A. The upper end of this die should be large enough to admit the coil and gradually taper to the size of the aperture in the headsheet of the condenser, as shown in the drawings. The coil of paper and glue being placed upon the punch or mandrel C, which has a shoulder, a, it is forced into the die by the downward motion ofthe mandrel as far as the taper of the die will permit the shoulder a to enter. The mandrel is then withdrawn, another coil placed upon it, which, in its descent, drives the first through the die, and so each coil being' forced through by the one next following. D is a vertical section, and D a crossscction, of the coil, after pressure in the die, and the packing is thus completed. E is a broken section of the head-sheet of a steam-comlenser, showing two apertures for tubes, one, F, with the paper cylinder D in place upon the tube G preparatory to swaging. rlhe aperture in the head-sheet is made only very little larger than the tube G from the inner surface I) for a small portion of the thickness-for the remaining portion the aperture being enlarged, forming an annular recess with a shoulder, e, at the bottom. .The paper cylinderl D occupies this recess. After the completed paper cylinder is placed upon the end of the tube in the said recess, as shown in Fig. 8, I take a suitable tool-preferably an annular punch corresponding in size with the end of the said cyl inder-and, by percussion, swage or upset the cylinder in its seat, so as to tighten it around the tube and cause it to fill completely the aunular recess in the head-sheet, thus forming a water and steam tight joint.

What I claim as my invention, and desire to secure by Letters Patent, is-

As a new manufacture, the compressed and consolidated cylinder D, composed of combined paper and glue formed and fitted for the packing of tubes in steam-coinlensers, as and for the purpose described.

WM. A. LIGHTHALL.

ln presence of B. S. CLARK, I. S. MAGKENZIE. 

